OPEN-SWE-TRACES: Advancing Dual-Mode Multilingual Distillation for Software Engineering Agents

Wasi Uddin Ahmad, Nikolai Ludwig, Somshubra Majumdar, Boris Ginsburg


Abstract
The path toward autonomous software engineering is currently bottlenecked by a severe deficit of diverse, large-scale trajectory data. We address this by introducing , an expansive dataset of 207,489 agentic trajectories spanning nine programming languages (Python, Go, TS, JS, Rust, Java, PHP, C, C++). Sourced from 20,000 real-world PRs via OpenHands and SWE-agent harnesses, the dataset utilizes a hybrid-reasoning synthesis: Minimax-M2.5 generates trajectories with explicit "thinking" processes, while Qwen3.5-122B provides high-quality behavioral traces. Filtered for permissive licenses (MIT, Apache, BSD) from SWE-rebench-V2, this data facilitates the training of models capable of long-horizon reasoning. We validate the dataset by fine-tuning the Qwen3-30B-A3B series (Thinking, Coder, and Instruct). The best performing model achieves a resolve rates of 60% on SWE-bench Verified, 46.2% on SWE-bench Multilingual, and 36.8% on SWE-bench Pro. These results establish as a premier resource for distilling human-level software engineering capabilities into efficient, open-source agentic LLMs.
Anthology ID:
2026.findings-emnlp.131
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
2668–2679
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.131/
DOI:
Bibkey:
Cite (ACL):
Wasi Uddin Ahmad, Nikolai Ludwig, Somshubra Majumdar, and Boris Ginsburg. 2026. OPEN-SWE-TRACES: Advancing Dual-Mode Multilingual Distillation for Software Engineering Agents. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 2668–2679, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
OPEN-SWE-TRACES: Advancing Dual-Mode Multilingual Distillation for Software Engineering Agents (Ahmad et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.131.pdf